Prognostic Factors of Pregnancy after Homologous Intrauterine Insemination

The objective was to identify the factors influencing the outcome of homologous intrauterine insemination (IUI-H). Nine hundred and sixty-eight couples underwent 2246 IUI-H cycles. The clinical pregnancy rate (PR) per IUI-H cycle and per couple, and the miscarriage and multiple pregnancy rates were 11.8%, 27.4%, 23.3%, and 12.0%, respectively. IUI-H for combined infertility (n = 118) was 3 times less efficient than IUI performed for unexplained infertility (n = 289), OR = 0.293 (95% CI, 0.098-0.872). PRs did not differ in CC, letrozole and gonadotropin cycles, but compared with CC, Gonal-F was twice as efficient, OR = 1.994 (95% CI, 1.137-3.495). The cycles with at least 3 follicles ≥17 mm were twice as successful as the cycles with 1 follicle only, OR = 1.836 (95% CI, 1.061-3.177). The success of IUI-H increases with higher inseminated motile sperm count (IMC), from 3.6×106 up to 12×106, where it reaches a plateau.